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The reproductive performance of Merino ewe lambs is highly variable and generally poor in comparison to older ewes. In this study, we determined the impacts of growth pattern to the end of the mating period and sire genetics on the reproductive performance of Merino ewe lambs. Five hundred ewe lambs with full pedigree records were managed under commercial conditions from weaning and weighed 43.5 kg at the start of the mating period with an average age of 224 days. The ewe lambs were offered a moderate or high feed allowance to achieve target growth rates of 100 or 200 g/day during a 46-day mating period. They were then recombined and scanned for pregnancy status 60 days after the mating period. At the individual animal level, a 5 kg greater live weight at the start of the mating period increased reproductive rate (foetuses per 100 ewes joined) by about 20% (P

Given the recent unique economic challenges and continued need to optimize lower completions, a new approach was successfully implemented offshore by Dubai Petroleum Establishment (DPE), an oil operator headquartered in Dubai, United Arab Emirates (UAE). In the unconventional carbonate source rock Shilaif formation at 8,400 ft true vertical depth (TVD), hydraulic fracturing including proppant was coupled with an openhole multistage (OHMS) ball drop sliding sleeve technology –– a first for offshore completions in the Middle East. This paper will discuss previous completion designs including acid stimulations and most recently an un-cemented completion liner using hydraulic fracturing and proppant. Having matrix-acidized the conventional carbonate formation on previous wells, DPE looked toward improving their stimulation methods for tight unconventional source rock to further enhance the recoverable reserves and continue to optimize the completion. Key factors evaluated before deciding to use the ball-drop activated sliding sleeves over the traditional plug and perforate (PnP) method of completion were benefits to safety, recovery potential, previous positive experience with the completion method, ease of installation, the ability to continuously pump the stimulation without shutting down (a large benefit in offshore completions) and a significant cost saving. A new technology was also implemented to confirm in real-time that the sliding sleeves functioned. Until now, surface pressure responses were the only indication the sleeves had functioned. This new technology allowed for real time sleeve shift verification that was independent from the usual pressure signature. The application required a unique, fit for purpose, completion system due to the demanding environment created by both the offshore conditions and the 15,000 psi differential rated equipment requirements for high stress unconventional rock. The tools were engineered, manufactured, and installed in a narrow timeframe that met the demanding offshore rig schedule. The system was then stimulated with a maximum surface treating pressure up to 10,000 psi in a continuous pumping operation. A total of 8 stages were successfully hydraulically stimulated with proppant without any major issues. All balls landed and shifted their respective sliding sleeves which were verified by real time pumping pressure response monitored at surface and independently with the new well monitoring technology used on this well, transmitting data to the main office. The technologies, methods and procedures presented in this paper are intended to show how DPE is leading the way in the region in reducing completion costs while safely working offshore. The completion solutions engineered and implemented for the placement of these offshore multistage proppant fracture stimulations have allowed DPE to unlock a significant volume of hydrocarbon reserves in the Dubai acreage, if not in the whole region.

The development of offshore unconventional reservoirs through hydraulic fracture stimulation has been debated for more than a decade. Attempted in isolated cases in small scale, such operations have been considered too complex, expensive, risky, and finally not economically attractive compared to other development opportunities. Technological breakthroughs in hydraulic fracturing in the past decade have enabled the renaissance of the oil and gas industry with the development of tight and source rock reservoirs mainly in onshore applicationsland in North America. New and dramatically improved operational efficiency standards have been set for fracturing in the last years. However, the same efficient operational set up, successful in onshore North America, cannot be directly emulated in an offshore environment due to limited space, more complex logistics, cost and environmental constraints. DPE, oil operator headquartered in Dubai-UAE, was able to overcome these challenges successfully and in 2016 drilled, completed and produced the world's first offshore horizontal multi-stage proppant fractured well that targeted a tight carbonate source rock, the Shilaif Formation at 8,400ft true vertical depth, source rock for most of the oil produced in Dubai. The successful concecusion of this project has allowed DPE to unlock a very significant volume of reserves in the Dubai acreage and possibly in the whole region. Albeit being one of the most complex and largest offshore stimulation jobs ever attempted, it was executed with minimum environmental impact; no freshwater was used, the post-frac flow-back was performed in a closed loop system where clean-up and production testing packages were specially designed conveying the flow-back fluids directly to the offshore production facility. The use of a modular type frac-package with continuous seawater mixing capability minimized environmental impact and avoided any freshwater consumption. The stimulation was executed from a lift boat, less sensitive to maritime conditions, which accommodated equipment and crews for continuous wellsite operation. Eight proppant fracturing treatments were performed in 48hr. Wellbore conditions and petrophysical data acquired while drilling allowed for a robust multi-stage open-hole completion design. The eight stage proppant fracturing treatment was engineered using channel fracturing techniques with 560,000 lb of proppant. This specific technique was applied to optimize proppant volumes and operational footprint while limiting screen-out risk in this complex reservoir stress setting and maximizing frac conductivity. This paper describes wellbore, completion, stimulation, clean-up and production testing design and planning that lead to this important technical success. It also highlights the potential of Dubai's offshore Shilaif resources. DPE's reservoir appraisal strategy followed during phase-one (2012-2016), potentially has opened the door to a new oil producing era in Dubai. This remarkable operation performed in the UAE with cutting edge technology and innovative operative integration was able to set a new efficiency benchmark, not only for well completion and fracturing operations within Middle East but also for offshore in general.